A display apparatus including a liquid crystal panel as an image display unit is configured in such a manner that a backlight (light-source device) is disposed on a back side of the liquid crystal panel, and light emitted from the backlight is modulated and transmitted by the liquid crystal panel so as to display an image on a front surface of the liquid crystal panel. The backlight is broadly classified into a direct type and an edge light type, but in recent years, to reduce power consumption and thin a frame, the edge light type backlight is widely employed.
The edge light type backlight includes a light guide plate and a light source which are housed in a backlight chassis (housing) formed in a shallow bottom box shape of which one surface is open. The light guide plate is a plate made of a translucent resin, and is placed on a bottom plate of the housing. The light source is disposed along one side wall of the housing, and is disposed to face one end face of the light guide plate, so as to face the one end face of the light guide plate.
Peripheral edge parts of the light guide plate are covered over an appropriate width of the light guide plate together with the light source by a frame body fitted to edge parts of the housing, and light emitted from the light source enters into the light guide plate and progresses in the light guide plate while being diffused, and then the light is distributed and emitted throughout the entirety of one surface of the light guide plate which is exposed to an inside of the housing (for example, see Japanese Patent Laid-open Publication No. 2007-232809).